The vehicle dumping apparatus of my U.S. Pat. No. 3,118,550, Jan. 21, 1964, has been very successful in the grain industry. It involves a grain truck on a platform elevated at one end by a fixed vertical cylinder which has a roller on its upper end in engagement with a curved track on the bottom side of the platform. The curved track is positioned such that the substantial downward pressure from the platform and truck is along the vertical axis of the cylinder thus minimizing horizontal forces on the cylinder which would tend to flex or bend it.
Other industries receive materials that can be very difficult to unload such as ear corn, wood chips, refuse, etc. These must be tilted too high and dangerous tilt angles to get the loads to break loose. When the material does begin to move, it can come down in one uncontrolled mass, at times damaging equipment and causing injury. Vibratory devices have been connected directly to the truck to shake it in an effort to loosen the material. The patent to R. W. Oglesby U.S. Pat. No. 2,284,226, May 26, 1942, is one example. This device, however, is not suitable for use with a truck raised at one end by an elevated platform. Thus, what is needed is a pulsation device that will move the platform and the truck as a unit while elevated at approximately a 30.degree. angle.